This is a proposal to isolate and determine the structure and the mechanism of action of four membrane transport systems: the (Na plus K ions) dependent adenosine triphosphatase involved in cation pumping; the glucose transport system which carries out facilitated diffusion of sugars; the anion transport system in human erythrocyte membranes involved in exchange diffusion of anions; and the adenylate cyclase system involved in hormone interactions. Finally, it is planned to characterize the erythrocyte membrane fibrous proteins involved in stabilization of the membrane. BIBLIOGRAPHIC REFERENCE: Ho, M.K.,and Guidotti, G. A Membrane Protein of Human Erythrocytes Involved in Anion Exchange. J. Biol. Chem. 250, 675, (1975).